Method of forming vanadium nitride layer and structure including the vanadium nitride layer

ABSTRACT

Methods and systems for depositing vanadium nitride layers onto a surface of the substrate and structures and devices formed using the methods are disclosed. An exemplary method includes using a cyclical deposition process, depositing a vanadium nitride layer onto a surface of the substrate. The cyclical deposition process can include providing a vanadium halide precursor to the reaction chamber and separately providing a nitrogen reactant to the reaction chamber. The cyclical deposition process may desirably be a thermal cyclical deposition process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 62/949,307 filed Dec. 17, 2019 titled METHOD OF FORMINGVANADIUM NITRIDE LAYER AND STRUCTURE INCLUDING THE VANADIUM NITRIDELAYER, the disclosure of which is hereby incorporated by reference inits entirety.

FIELD OF INVENTION

The present disclosure generally relates to methods and systems suitablefor forming a layer on a surface of a substrate and to structuresincluding the layer. More particularly, the disclosure relates tomethods and systems for forming layers that include vanadium nitride andto structures formed using the methods and systems.

BACKGROUND OF THE DISCLOSURE

The scaling of semiconductor devices, such as, for example,complementary metal-oxide-semiconductor (CMOS) devices, has led tosignificant improvements in speed and density of integrated circuits.However, conventional device scaling techniques face significantchallenges for future technology nodes.

For example, one challenge has been finding a suitable conductingmaterial for use as a gate electrode in the CMOS devices. CMOS deviceshave conventionally used n-type doped polysilicon as the gate electrodematerial. However, doped polysilicon may not be an ideal gate electrodematerial for advanced node applications. Although doped polysilicon isconductive, there may still be a surface region which can be depleted ofcarriers under bias conditions. This region may appear as an extra gateinsulator thickness, commonly referred to as gate depletion, and maycontribute to the equivalent oxide thickness. While the gate depletionregion may be thin, on the order of a few angstroms (A), the gatedepletion region may become significant as the gate oxide thicknessesare reduced in advanced node applications. As a further example,polysilicon does not exhibit an ideal effective work function (eWF) forboth NMOS and PMOS devices. To overcome the non-ideal effective workfunction of doped polysilicon, a threshold voltage adjustmentimplantation may be utilized. However, as device geometries reduce inadvanced node applications, the threshold voltage adjustmentimplantation processes may become increasingly complex and impractical.

To overcome problems associated with doped polysilicon gate electrodes,polysilicon gate material may be replaced with an alternative material,such as, for example, a titanium nitride layer. The titanium nitridelayer may provide a more ideal effective work function for CMOSapplications. However, in some cases, where higher work function valuesthan those obtained with titanium nitride layers—e.g., in PMOS regionsof a CMOS device—are desired, improved materials for gate electrodes aredesired. Such materials may also be suitable for otherelectrode/capacitor applications, such as dynamic random access memory(DRAM) applications, as well as other applications.

Any discussion, including discussion of problems and solutions, setforth in this section has been included in this disclosure solely forthe purpose of providing a context for the present disclosure. Suchdiscussion should not be taken as an admission that any or all of theinformation was known at the time the invention was made or otherwiseconstitutes prior art.

SUMMARY OF THE DISCLOSURE

This summary may introduce a selection of concepts in a simplified form,which may be described in further detail below. This summary is notintended to necessarily identify key features or essential features ofthe claimed subject matter, nor is it intended to be used to limit thescope of the claimed subject matter.

Various embodiments of the present disclosure relate to methods offorming structures including vanadium nitride layers, to structures anddevices formed using such methods, and to apparatus for performing themethods and/or for forming the structures and/or devices. While the waysin which various embodiments of the present disclosure address drawbacksof prior methods and systems are discussed in more detail below, ingeneral, various embodiments of the disclosure provide improved methodsof forming vanadium nitride layers that exhibit relatively high workfunction values. Additionally or alternatively, vanadium nitride layerscan be formed using one or more vanadium halide precursors. Further,exemplary vanadium nitride layers can be formed using a thermal cyclicaldeposition process—without using a plasma or plasma-activated species.

In accordance with exemplary embodiments of the disclosure, a method offorming a gate electrode structure is disclosed. Exemplary methods offorming the gate electrode structure include providing a substratewithin a reaction chamber of a reactor and, using a cyclical depositionprocess, depositing a vanadium nitride layer onto a surface of thesubstrate. The cyclical deposition process can include (e.g.,sequentially and separately) providing a vanadium halide precursor tothe reaction chamber and providing a nitrogen reactant to the reactionchamber. The vanadium halide precursor can include one or more of avanadium halide and a vanadium oxyhalide. The vanadium halide can beselected from the group consisting of vanadium fluoride, vanadiumchloride, vanadium bromide, vanadium iodide, and the like. The vanadiumoxyhalide can be selected from the group consisting of a vanadiumoxyfluoride, a vanadium oxychloride, a vanadium oxybromide, a vanadiumoxyiodide, and the like. The nitrogen reactant can be selected from oneor more of ammonia (NH₃), hydrazine (N₂H₄), other nitrogen andhydrogen-containing gases, and the like. The cyclical deposition processcan include one or more of an atomic layer deposition process and acyclical chemical vapor deposition process. The cyclical depositionprocess can include a thermal process—i.e., a process that does not useplasma-activated species. Use of a thermal process may be desirable forsome applications, such as formation of gate structures, because use ofplasma for such applications may be detrimental to device performance.

In accordance with further exemplary embodiments of the disclosure, amethod of forming a structure comprising a vanadium nitride layerincludes providing a substrate within a reaction chamber of a reactorand, using a thermal cyclical deposition process, depositing a layercomprising vanadium nitride onto a surface of the substrate. The thermalcyclical deposition process can include providing a vanadium halideprecursor to the reaction chamber and providing a nitrogen reactant tothe reaction chamber. The vanadium halide precursor and the nitrogenreactant can be the same or similar to the vanadium halide precursor andthe nitrogen reactant described above and elsewhere herein. Inaccordance with examples of the disclosure, the thermal cyclicaldeposition process does not include use of a nitrogen plasma, does notinclude use of excited nitrogen species, does not include use ofnitrogen radicals, and/or does not include use of diatomic nitrogen as anitrogen reactant.

In accordance with yet further exemplary embodiments of the disclosure,a structure is formed using a method as described herein. The structurecan include a substrate and a vanadium nitride layer formed overlying asurface of the substrate. Exemplary structures can further include oneor more additional layers, such as an additional metal or conductinglayer overlying the vanadium nitride layer. The structure can be or formpart of a CMOS structure, such as one or more of a PMOS and NMOSstructure.

In accordance with yet additional embodiments of the disclosure, adevice or portion thereof can be formed using a method and/or astructure as described herein. The device can include a substrate, aninsulating or dielectric layer, a vanadium nitride layer overlying theinsulating or dielectric layer, and optionally an additional metal layeroverlying the vanadium nitride layer. The device can be or form part ofa CMOS device.

In accordance with yet additional examples of the disclosure, a systemto perform a method as described herein and/or to form a structure,device, or portion of either, is disclosed.

These and other embodiments will become readily apparent to thoseskilled in the art from the following detailed description of certainembodiments having reference to the attached figures. The invention isnot being limited to any particular embodiments disclosed.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of the embodiments of the presentdisclosure may be derived by referring to the detailed description andclaims when considered in connection with the following illustrativefigures.

FIG. 1 illustrates a method in accordance with exemplary embodiments ofthe disclosure.

FIG. 2 illustrates a structure/device portion in accordance withexemplary embodiments of the disclosure.

FIG. 3 illustrates a reactor system in accordance with additionalexemplary embodiments of the disclosure.

It will be appreciated that elements in the figures are illustrated forsimplicity and clarity and have not necessarily been drawn to scale. Forexample, the dimensions of some of the elements in the figures may beexaggerated relative to other elements to help improve understanding ofillustrated embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The description of exemplary embodiments of methods, structures, devicesand systems provided below is merely exemplary and is intended forpurposes of illustration only; the following description is not intendedto limit the scope of the disclosure or the claims. Moreover, recitationof multiple embodiments having stated features is not intended toexclude other embodiments having additional features or otherembodiments incorporating different combinations of the stated features.For example, various embodiments are set forth as exemplary embodimentsand may be recited in the dependent claims. Unless otherwise noted, theexemplary embodiments or components thereof may be combined or may beapplied separate from each other.

As set forth in more detail below, various embodiments of the disclosureprovide methods for forming structures, such as gate electrodestructures. Exemplary methods can be used to, for example, form CMOSdevices or portions thereof. However, unless noted otherwise, theinvention is not necessarily limited to such examples.

Further, exemplary methods can include forming a vanadium nitride layerusing a cyclical deposition process. In accordance with examples of thedisclosure, a (e.g., thermal) cyclical deposition process includesproviding a vanadium halide precursor to the reaction chamber andproviding a nitrogen reactant to the reaction chamber. In accordancewith these examples, no activated species, such as radicals, ions, orthe like, are formed using a plasma.

In this disclosure, “gas” can include material that is a gas at normaltemperature and pressure (NTP), a vaporized solid and/or a vaporizedliquid, and can be constituted by a single gas or a mixture of gases,depending on the context. A gas other than the process gas, i.e., a gasintroduced without passing through a gas distribution assembly, othergas distribution device, or the like, can be used for, e.g., sealing thereaction space, and can include a seal gas, such as a rare gas. In somecases, the term “precursor” can refer to a compound that participates inthe chemical reaction that produces another compound, and particularlyto a compound that constitutes a film matrix or a main skeleton of afilm; the term “reactant” can be used interchangeably with the termprecursor. The term “inert gas” can refer to a gas that does not takepart in a chemical reaction and/or does not become a part of a filmmatrix to an appreciable extent. Exemplary inert gases include He and Arand any combination thereof. In some cases, nitrogen and/or hydrogen canbe an inert gas.

As used herein, the term “substrate” can refer to any underlyingmaterial or materials that can be used to form, or upon which, a device,a circuit, or a film can be formed. A substrate can include a bulkmaterial, such as silicon (e.g., single-crystal silicon), other Group IVmaterials, such as germanium, or other semiconductor materials, such asa Group II-VI or Group III-V semiconductor materials, and can includeone or more layers overlying or underlying the bulk material. Further,the substrate can include various features, such as recesses,protrusions, and the like formed within or on at least a portion of alayer of the substrate. By way of examples, a substrate can include bulksemiconductor material and an insulating or dielectric material layeroverlying at least a portion of the bulk semiconductor material.

As used herein, the term “film” and/or “layer” can refer to anycontinuous or non-continuous structure and material, such as materialdeposited by the methods disclosed herein. For example, film and/orlayer can include two-dimensional materials, three-dimensionalmaterials, nanoparticles or even partial or full molecular layers orpartial or full atomic layers or clusters of atoms and/or molecules. Afilm or layer may comprise material or a layer with pinholes, which maybe at least partially continuous.

As used herein, a “structure” can be or include a substrate as describedherein. Structures can include one or more layers overlying thesubstrate, such as one or more layers formed according to a method asdescribed herein.

The term “cyclic deposition process” or “cyclical deposition process”can refer to the sequential introduction of precursors (and/orreactants) into a reaction chamber to deposit a layer over a substrateand includes processing techniques such as atomic layer deposition(ALD), cyclical chemical vapor deposition (cyclical CVD), and hybridcyclical deposition processes that include an ALD component and acyclical CVD component.

The term “atomic layer deposition” can refer to a vapor depositionprocess in which deposition cycles, typically a plurality of consecutivedeposition cycles, are conducted in a process chamber. The term atomiclayer deposition, as used herein, is also meant to include processesdesignated by related terms, such as chemical vapor atomic layerdeposition, when performed with alternating pulses ofprecursor(s)/reactive gas(es), and purge (e.g., inert carrier) gas(es).

Generally, for ALD processes, during each cycle, a precursor isintroduced to a reaction chamber and is chemisorbed to a depositionsurface (e.g., a substrate surface that can include a previouslydeposited material from a previous ALD cycle or other material), formingabout a monolayer or sub-monolayer of material that does not readilyreact with additional precursor (i.e., a self-limiting reaction).Thereafter, in some cases, a reactant (e.g., another precursor orreaction gas) may subsequently be introduced into the process chamberfor use in converting the chemisorbed precursor to the desired materialon the deposition surface. The reactant can be capable of furtherreaction with the precursor. Purging steps can be utilized during one ormore cycles, e.g., during each step of each cycle, to remove any excessprecursor from the process chamber and/or remove any excess reactantand/or reaction byproducts from the reaction chamber.

As used herein, a “vanadium nitride layer” can be a material layer thatcan be represented by a chemical formula that includes vanadium andnitrogen. A vanadium nitride layer can include additional elements, suchas oxygen (e.g., a vanadium oxynitride layer) and the like.

As used herein, a “vanadium halide precursor” includes a gas or amaterial that can become gaseous and that can be represented by achemical formula that includes vanadium and a halogen, such as one ormore of fluorine (F), chlorine (CI), bromine (Br), and iodine (I).

The term “nitrogen reactant” can refer to a gas or a material that canbecome gaseous and that can be represented by a chemical formula thatincludes nitrogen. In some cases, the chemical formula includes nitrogenand hydrogen. In some cases, the nitrogen reactant does not includediatomic nitrogen.

Further, in this disclosure, any two numbers of a variable canconstitute a workable range of the variable, and any ranges indicatedmay include or exclude the endpoints. Additionally, any values ofvariables indicated (regardless of whether they are indicated with“about” or not) may refer to precise values or approximate values andinclude equivalents, and may refer to average, median, representative,majority, or the like. Further, in this disclosure, the terms“including,” “constituted by” and “having” refer independently to“typically or broadly comprising,” “comprising,” “consisting essentiallyof,” or “consisting of” in some embodiments. In this disclosure, anydefined meanings do not necessarily exclude ordinary and customarymeanings in some embodiments.

Turning now to the figures, FIG. 1 illustrates a method 100 inaccordance with exemplary embodiments of the disclosure. Method 100 canbe used to, for example, form a gate electrode structure suitable forNMOS, PMOS, and/or CMOS devices. However, unless otherwise noted,methods are not limited to such applications.

Method 100 includes the steps of providing a substrate within a reactionchamber of a reactor (step 102) and using a cyclical deposition process,depositing a layer comprising vanadium nitride onto a surface of thesubstrate (step 104).

During step 102, a substrate is provided within a reaction chamber. Thereaction chamber used during step 102 can be or include a reactionchamber of a chemical vapor deposition reactor system configured toperform a cyclical deposition process. The reaction chamber can be astand-alone reaction chamber or part of a cluster tool.

Step 102 can include heating the substrate to a desired depositiontemperature within the reaction chamber. In some embodiments of thedisclosure, step 102 includes heating the substrate to a temperature ofless than 800° C. For example, in some embodiments of the disclosure,heating the substrate to a deposition temperature may comprise heatingthe substrate to a temperature between approximately 20° C. andapproximately 800° C.

In addition to controlling the temperature of the substrate, a pressurewithin the reaction chamber may also be regulated. For example, in someembodiments of the disclosure, the pressure within the reaction chamberduring step 102 may be less than 760 Torr or between 10 Torr and 760Torr.

During step 104, a vanadium nitride layer is deposited onto a surface ofthe substrate using a cyclical deposition process. As noted above, thecyclical deposition process can include cyclical CVD, ALD, or a hybridcyclical CVD/ALD process. For example, in some embodiments, the growthrate of a particular ALD process may be low compared with a CVD process.One approach to increase the growth rate may be that of operating at ahigher deposition temperature than that typically employed in an ALDprocess, resulting in some portion of a chemical vapor depositionprocess, but still taking advantage of the sequential introduction ofreactants. Such a process may be referred to as cyclical CVD. In someembodiments, a cyclical CVD process may comprise the introduction of twoor more reactants into the reaction chamber, wherein there may be a timeperiod of overlap between the two or more reactants in the reactionchamber resulting in both an ALD component of the deposition and a CVDcomponent of the deposition. This is referred to as a hybrid process.For example, a cyclical deposition process may comprise the continuousflow of one reactant and the periodic pulsing of a second reactant intothe reaction chamber.

In accordance with examples of the disclosure, the cyclical depositionprocess is a thermal deposition process. In these cases, the cyclicaldeposition process does not include use of a plasma to form activatedspecies for use in the cyclical deposition process. For example, thecyclical deposition process may not comprise formation or use of anitrogen plasma, may not comprise formation or use of excited nitrogenspecies, and/or may not comprise formation or use or nitrogen radicals.

The cyclical deposition process can include (e.g., separately and/orsequentially) providing a vanadium halide precursor to the reactionchamber and providing a nitrogen reactant to the reaction chamber. Thevanadium halide precursor can include one or more of a vanadium halideand a vanadium oxyhalide. By way of examples, the vanadium halide can beselected from one or more of a vanadium fluoride, a vanadium chloride, avanadium bromide, and a vanadium iodide. The vanadium halide can includeonly vanadium and one or more halogens. By way of example, the vanadiumhalide can include vanadium tetrachloride or the like. The vanadiumoxyhalide can be selected from one or more of vanadium oxyhalides, suchas one or more of a vanadium oxyfluoride, a vanadium oxychloride, avanadium oxybromide, and a vanadium oxyiodide. The vanadium oxyhalidecan include only vanadium, oxygen, and one or more halides. By way ofexample, the vanadium oxyhalide can include vanadium oxytrichloride orthe like. Use of vanadium halide precursors can be advantageous relativeto methods that use other precursors, such as vanadium metalorganicprecursors, because the vanadium halide precursors can be relativelyinexpensive, can result in vanadium nitride layers with lowerconcentrations of impurities, such as carbon, and/or processes that usesuch precursors can be more controllable—compared to processes that usemetalorganic or other vanadium precursors. Further, such reactants canbe used without the assistance of a plasma to form excited species. Inaddition, processes that use vanadium halide may be easier to scale up,compared to methods that use organometallic vanadium precursors.

The nitrogen reactant can be or include one or more of ammonia (NH₃),hydrazine (N₂H₄), or the like. The nitrogen reactant can include orconsist of nitrogen and hydrogen. In some cases, the nitrogen reactantdoes not include diatomic nitrogen. In the case of thermal cyclicaldeposition processes, a duration of the step of providing nitrogenreactant to the reaction chamber can be relatively long to allow thenitrogen reactant to react with the precursor or a derivative thereof.For example, the duration can be greater than or equal to 5 seconds orgreater than or equal to 10 seconds or between about 5 and 10 seconds.

As part of step 104, the reaction chamber can be purged using a vacuumand/or an inert gas, to mitigate gas phase reactions between reactantsand enable self-saturating surface reactions—e.g., in the case of ALD.Additionally or alternatively, the substrate may be moved to separatelycontact a first vapor phase reactant and a second vapor phase reactant.Surplus chemicals and reaction byproducts, if any, can be removed fromthe substrate surface or reaction chamber, such as by purging thereaction space or by moving the substrate, before the substrate iscontacted with the next reactive chemical. The reaction chamber can bepurged after the step of providing a vanadium halide precursor to thereaction chamber and/or after the step of providing a nitrogen reactantto the reaction chamber.

In some embodiments of the disclosure, method 100 includes repeating aunit deposition cycle that includes (1) providing a vanadium halideprecursor to the reaction chamber and (2) providing a nitrogen reactantto the reaction chamber, with optional purge or move steps after step(1) and/or (2). The deposition cycle can be repeated one or more times,based on, for example, desired thickness of the vanadium nitride layer.For example, if the thickness of the vanadium nitride layer is less thandesired for a particular application, then the step of providing avanadium halide precursor to the reaction chamber and providing anitrogen reactant to the reaction chamber can be repeated one or moretimes. Once the vanadium nitride layer has been deposited to a desiredthickness, the substrate can be subjected to additional processes toform a device structure and/or device.

In some embodiments, a step coverage of the vanadium nitride layer isequal to or greater than about 50%, or greater than about 80%, orgreater than about 90%, or about 95%, or about 98%, or about 99% orgreater, in/on structures having aspect ratios (height/width) of morethan about 2, more than about 5, more than about 10, more than about 25,more than about 50, or even more than about 100.

FIG. 2 illustrates a structure/a portion of a device 200 in accordancewith additional examples of the disclosure. of a device or structure 200includes a substrate 202, dielectric or insulating material 204, andvanadium nitride layer 206. In the illustrated example, structure 200also includes an additional conducting layer 212.

Substrate 202 can be or include any of the substrate material describedherein. In the illustrated example, substrate 202 includes a sourceregion 214, a drain region 216, and a channel region 218. Althoughillustrated as a horizontal structure, structures and devices inaccordance with examples of the disclosure can include vertical and/orthree-dimensional structures and devices, such as FinFET devices.

Dielectric or insulating material 204 can include one or more dielectricor insulating materials suitable for gate structure applications. By wayof example, dielectric or insulating material 204 can include aninterface layer 208 and a high-k material 210 deposited overlyinginterface layer 208. In some cases, interface layer 208 may not exist ormay not exist to an appreciable extent. Interface layer 208 can includean oxide, such as a silicon oxide, which can be formed on a surface ofthe substrate 202 using, for example a chemical oxidation process or anoxide deposition process. High-k material 210 can be or include, forexample, a metallic oxide having a dielectric constant greater thanapproximately 7. In some embodiments, the high-k material includes has adielectric constant higher than the dielectric constant of siliconoxide. Exemplary high-k materials include one or more of hafnium oxide(HfO₂), tantalum oxide (Ta₂O₅), zirconium oxide (ZrO₂), titanium oxide(TiO₂), hafnium silicate (HfSiO_(x)), aluminum oxide (A1 ₂O₃) orlanthanum oxide (La₂O₃), or mixtures/laminates thereof.

Vanadium nitride layer 206 can be formed according to a method describedherein. Because vanadium nitride layer 206 is formed using a cyclicaldeposition process, a concentration of vanadium and/or nitrogen can varyfrom a bottom of vanadium nitride layer 206 to a top of vanadium nitridelayer 206 by, for example, controlling an amount of vanadium halideprecursor and/or nitrogen reactant and/or respective pulse times duringone or more deposition cycles. In some cases, vanadium nitride layer 206can have a stochiometric composition. A work function and otherproperties of vanadium nitride layer 206 can be altered by altering anamount of nitrogen and/or vanadium in the layer or in a depositioncycle.

Vanadium nitride layer 206 can include oxygen. For example, vanadiumnitride layer 206 can be or include a vanadium oxynitride layer.Vanadium nitride layer 206 can include impurities, such as halides,hydrogen or the like in an amount of less than one atomic percent, lessthan 0.2 atomic percent, or less than about 0.1 atomic percent, or lessthan 0.05 atomic percent, alone or combined.

A work function of vanadium nitride layer 206 can be >4.6 eV, >4.7eV, >4.8 eV, >4.9 eV, >4.95 eV, or >5.0 eV. Additionally oralternatively, vanadium nitride layer 206 can form a continuousfilm—e.g., using method 100—at a thickness of less than <5 nm, <4 nm, <3nm, <2 nm, <1.5 nm, <1.2 nm, <1.0 nm, or <0.9 nm. Vanadium nitride layer206 can be relatively smooth, with relatively low grain boundaryformation. In some cases, vanadium nitride layer 206 may be amorphous,with relatively low columnar crystal structures (as compared to TiN).RMS roughness of exemplary vanadium nitride layer 206 can be <1.0 nm,<0.7 nm, <0.5 nm, <0.4 nm, <0.35 nm, <0.3 nm, at a thickness of lessthan 10 nm.

Additional conducting layer 212 can include, for example, metal, such asa refractory metal or the like.

FIG. 3 illustrates a system 300 in accordance with yet additionalexemplary embodiments of the disclosure. System 300 can be used toperform a method as described herein and/or form a structure or deviceportion as described herein.

In the illustrated example, system 300 includes one or more reactionchambers 302, a precursor gas source 304, a nitrogen reactant gas source306, a purge gas source 308, an exhaust source 310, and a controller312.

Reaction chamber 302 can include any suitable reaction chamber, such asan ALD or CVD reaction chamber.

Precursor gas source 304 can include a vessel and one or more vanadiumhalide precursors as described herein—alone or mixed with one or morecarrier (e.g., inert) gases. Nitrogen reactant gas source 306 caninclude a vessel and one or more nitrogen reactants as describedherein—alone or mixed with one or more carrier gases. Purge gas source308 can include one or more inert gases as described herein. Althoughillustrated with three gas sources 304-308, system 300 can include anysuitable number of gas sources. Gas sources 304-308 can be coupled toreaction chamber 302 via lines 314-318, which can each include flowcontrollers, valves, heaters, and the like.

Exhaust source 310 can include one or more vacuum pumps.

Controller 312 includes electronic circuitry and software to selectivelyoperate valves, manifolds, heaters, pumps and other components includedin the system 300. Such circuitry and components operate to introduceprecursors, reactants, and purge gases from the respective sources304-308. Controller 312 can control timing of gas pulse sequences,temperature of the substrate and/or reaction chamber, pressure withinthe reaction chamber, and various other operations to provide properoperation of the system 300. Controller 312 can include control softwareto electrically or pneumatically control valves to control flow ofprecursors, reactants and purge gases into and out of the reactionchamber 302. Controller 312 can include modules such as a software orhardware component, e.g., a FPGA or ASIC, which performs certain tasks.A module can advantageously be configured to reside on the addressablestorage medium of the control system and be configured to execute one ormore processes.

Other configurations of system 300 are possible, including differentnumbers and kinds of precursor and reactant sources and purge gassources. Further, it will be appreciated that there are manyarrangements of valves, conduits, precursor sources, and purge gassources that may be used to accomplish the goal of selectively feedinggases into reaction chamber 302. Further, as a schematic representationof a system, many components have been omitted for simplicity ofillustration, and such components may include, for example, variousvalves, manifolds, purifiers, heaters, containers, vents, and/orbypasses.

During operation of reactor system 300, substrates, such assemiconductor wafers (not illustrated), are transferred from, e.g., asubstrate handling system to reaction chamber 302. Once substrate(s) aretransferred to reaction chamber 302, one or more gases from gas sources304-308, such as precursors, reactants, carrier gases, and/or purgegases, are introduced into reaction chamber 302.

The example embodiments of the disclosure described above do not limitthe scope of the invention, since these embodiments are merely examplesof the embodiments of the invention, which is defined by the appendedclaims and their legal equivalents. Any equivalent embodiments areintended to be within the scope of this invention. Indeed, variousmodifications of the disclosure, in addition to those shown anddescribed herein, such as alternative useful combinations of theelements described, may become apparent to those skilled in the art fromthe description. Such modifications and embodiments are also intended tofall within the scope of the appended claims.

1. A method of forming a gate electrode structure, the method comprisingthe steps of: providing a substrate within a reaction chamber of areactor; and using a cyclical deposition process, depositing a vanadiumnitride layer onto a surface of the substrate, wherein the cyclicaldeposition process comprises: providing a vanadium halide precursor tothe reaction chamber; and providing a nitrogen reactant to the reactionchamber.
 2. The method of claim 1, wherein the vanadium halide precursorcomprises one or more of a vanadium halide and a vanadium oxyhalide. 3.The method of claim 2, wherein the vanadium halide is selected from thegroup consisting of a vanadium fluoride, a vanadium chloride, a vanadiumbromide, and a vanadium iodide.
 4. The method of claim 2, wherein thevanadium oxyhalide is selected from the group consisting of a vanadiumoxyfluoride, a vanadium oxychloride, a vanadium oxybromide, and avanadium oxyiodide.
 5. The method of claim 1, wherein the cyclicaldeposition process comprises an atomic layer deposition process.
 6. Themethod of claim 1, wherein the cyclical deposition process comprises acyclical chemical vapor deposition process.
 7. The method of claim 1,wherein the cyclical deposition process comprises a thermal process. 8.The method of claim 1, wherein a duration of the step of providing thenitrogen reactant to the reaction chamber is greater than or equal to 5seconds, or greater than or equal to 10 seconds, or between about 5seconds and about 10 seconds.
 9. The method of claim 1, wherein atemperature of the substrate within the reaction chamber during thecyclical deposition process is between about 20° C. and about 800° C.10. The method of claim 1, wherein a pressure within the reactionchamber during the cyclical deposition process is less than 760 Torr.11. The method of claim 1, wherein the nitrogen reactant is selectedfrom one or more of ammonia (NH₃), hydrazine (N₂H₄), and other compoundscomprising or consisting of nitrogen and hydrogen.
 12. The method ofclaim 1, wherein the nitrogen reactant does not include diatomicnitrogen.
 13. A method of forming a structure comprising a vanadiumnitride layer, the method comprising the steps of: providing a substratewithin a reaction chamber of a reactor; and using a thermal cyclicaldeposition process, depositing a layer comprising vanadium nitride ontoa surface of the substrate, wherein the thermal cyclical depositionprocess comprises: providing a vanadium halide precursor to the reactionchamber; and providing a nitrogen reactant to the reaction chamber. 14.The method of claim 13, wherein the vanadium halide precursor comprisesone or more of a vanadium halide and a vanadium oxyhalide.
 15. Themethod of claim 13, wherein the nitrogen reactant is selected from oneor more of ammonia (NH₃), hydrazine (N₂H₄), and other compoundscomprising or consisting of nitrogen and hydrogen.
 16. The method ofclaim 13, wherein the nitrogen reactant does not include diatomicnitrogen.
 17. The method of claim 13, wherein the thermal cyclicaldeposition process comprises one or more of a cyclical chemical vapordeposition process and an atomic layer deposition process.
 18. Themethod of claim 1, wherein the thermal cyclical deposition process doesnot comprise use of a nitrogen plasma.
 19. The method of claim 1,wherein the thermal cyclical deposition process does not comprise use ofexcited nitrogen species.
 20. The method of claim 1, wherein the thermalcyclical deposition process does not comprise use of nitrogen radicals.21. A structure comprising a vanadium nitride layer formed according tothe method of claim
 1. 22. The structure of claim 21, wherein a workfunction of the vanadium nitride layer is >4.6 eV, >4.7 eV, >4.8eV, >4.9 eV, >4.95 eV, or >5.0 eV.
 23. The structure of claim 21,wherein a RMS roughness of the vanadium nitride layer is <1.0 nm, <0.7nm, <0.5 nm, <0.4 nm, <0.35 nm, or <0.3 nm at a thickness of less than10 nm.
 24. A system comprising: one or more reaction chambers; aprecursor gas source comprising a vanadium halide precursor; a nitrogenreactant gas source; an exhaust source; and a controller, wherein thecontroller is configured to control gas flow into at least one of theone or more reaction chambers to form a vanadium nitride layer overlyinga surface of a substrate using a thermal cyclical deposition process.